The present invention relates to a pump for pumping fluid media (gases or liquids). In particular, but not exclusively, the present invention relates to a vacuum pump configured as regenerative vacuum pump.
The present invention is described below with reference to vacuum pumps, although it is understood that the invention is not limited in any way to vacuum pumps and can equally apply to other types of pump, such as liquid pumps, gas compressors, or the like.
Vacuum pumps which comprise a regenerative pumping mechanism are known hereto. Known regenerative pumping mechanisms comprise a plurality of annular arrays of rotor blades which are mounted on a rotor and extend axially from the rotor into respective annular channels formed in a stator. Rotation of the rotor causes the blades to travel along the channels forming a gas vortex which flows along a flow path between an inlet and an outlet of the pumping mechanism.
Examples of this type of vacuum pump are known in the art and specific variations of the pump are described in EP0568069 and EP1170508. Regenerative pumping mechanisms described in these documents can comprise a rotor which is formed in a disc-like configuration with pump elements on either side of the rotor. The pumped gas follows a flow path arranged such that the gas flows along one side of the rotor from an inlet and is then transferred in a serial fashion to the other side of the rotor and thence onwards to an outlet.